“It is difficult to comprehend that the going rate for a public holiday is £890 per day and I would be interested to know how much of this sum was paid to the nurse and how much was retained by the agency.”

NHS Ayrshire and Arran admitted that while they have cut their total agency nursing costs by two-thirds, they still pay up to £60 per hour per nurse.

Figures from NHS Borders have shown that the health board pays up to £57.50 per hour while NHS Highland paid £50 per hour, and spending £426,130 on agency nurses last year.

The figures, released under Freedom of Information laws, showed that the total spent on agency nurses has been cut drastically over the last five years from a peak of £29million in 2003-2004.

The figures did show that many of Scotland’s health boards have managed to significantly cut down on agency spending, with most showing lower spending than five years ago.

Health boards, with most supplying documents from April 2008 to March 2009, and with several supplying documents up to November 2009, showed a total of £12.9million spent on agency costs.

However, NHS Highland showed they spent £90,000 more last year than in 2004-2005, going from £335,262, to £426,130.

And NHS Grampian had admitted they spent half a million pounds more last year, £1.48m, than they did five years ago on agency nurses, £1million, despite pledges across health boards to cut down costs.

Bridget Hunter, UNISON Scotland’s lead officer for nursing, said the significant fee that the agencies take themselves could be used to employ many more nurses within the NHS.

She also warned that the NHS faces a nursing crisis, with too few full time specialist nurses in particular coming through the training programmes.

Ms Hunter said: “UNISON has long campaigned to decrease the use of nursing agencies.

“The extra mark-up for their profit entails means that less is available to employ more nurses or to pay them better.

“Board costs show that NHS staff, whether full-time, part-time or bank, cost less to employ, while giving nurses proper NHS pay and conditions.”

“These figures show that we have made progress in reducing the level of agency use from the £29m that Health Minister, Malcolm Chisholm said was unacceptable back in 2003/4.

“We are also aware that there has been a welcome increase in the use of NHS banks for nursing cover.

“However, further reducing the use of expensive agency cover will be difficult, as we continue to lose experienced nurses – particularly specialists.

“We are still not training enough nurses to fill the increasing staffing gaps, and this needs to be seriously addressed, and quickly.”

A health spokesman for the Scottish Government said: “While it is for individual NHS boards to ensure they are getting maximum value for money from employing temporary staff, there is a general drive across the NHS to reduce reliance on agency staff.

“Since 2004/5, spending on agency staff has been cut by 60 per cent, from £26.4million to £10.4million, and this now accounts for just 0.5 per cent of spending on nursing and midwifery staff.

“This shift away from agency staff has been accompanied by greater use of the NHS nurse bank.

“As NHS employees, they provide better value for money than agency nurses. Bank staff account for 4.7 per cent of the overall nursing and midwifery costs in NHS Scotland.”